G'day from Queensland Australia.
I have a 2006 Jazz with only 31000km.
Just before Christmas 2009 the daytime temperatures were about 35 to 38 degrees Celsius in the sun.
Our car due to having no alternative, is always parked with the right hand side of the car towards the sun, and with the windows up rapidly reaches 50 to 60 degrees celsius.
After a couple of weeks when the rain came I noticed water in the rear right foot well.
I traced the leak to the fact that Honda chose (at least in the Thailand production cars) to use some sort of black sealer similar to bitumen to stick down the door liner membrane. In the heat the sealer had softened and the membrane had lifted allowing water to enter the car over the door sills instead of exiting through the door drainage holes.
The simple fix was to remove the front & rear door trim, then remove the liner membrane and wash it in cleaning solvent to remove all traces of the "bitumen".
You also then need to clean all traces off the metal door.
I replaced the "bitumen" with a product called "sikaflex - 227" which is a cream coloured paste that I obtained (along with the previously mentioned cleaning solvent) from my local automotive accessory shop.
The good news is that even with the flooding rain (about 300mm or 1ft just in one night) that we have had here in the last 4 days not a drop got in to the car.
